/*
* Conditions Of Use 
* 
* This software was developed by employees of the National Institute of
* Standards and Technology (NIST), an agency of the Federal Government.
* Pursuant to title 15 Untied States Code Section 105, works of NIST
* employees are not subject to copyright protection in the United States
* and are considered to be in the public domain.  As a result, a formal
* license is not needed to use the software.
* 
* This software is provided by NIST as a service and is expressly
* provided "AS IS."  NIST MAKES NO WARRANTY OF ANY KIND, EXPRESS, IMPLIED
* OR STATUTORY, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTY OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, NON-INFRINGEMENT
* AND DATA ACCURACY.  NIST does not warrant or make any representations
* regarding the use of the software or the results thereof, including but
* not limited to the correctness, accuracy, reliability or usefulness of
* the software.
* 
* Permission to use this software is contingent upon your acceptance
* of the terms of this agreement
*  
* .
* 
*/
/******************************************************************************
 * Product of NIST/ITL Advanced Networking Technologies Division (ANTD).      *
 ******************************************************************************/
package gov.nist.javax.sip.header;

import gov.nist.javax.sip.message.SIPRequest;

import javax.sip.InvalidArgumentException;
import javax.sip.header.CSeqHeader;
import java.text.ParseException;

/**
 *  CSeq SIP Header.
 *
 * @author M. Ranganathan    <br/>
 * @version 1.2 $Revision: 1.8 $ $Date: 2007/02/12 15:19:20 $
 * @since 1.1
 *
 */

public class CSeq extends SIPHeader implements javax.sip.header.CSeqHeader {

	/**
	 * Comment for <code>serialVersionUID</code>
	 */
	private static final long serialVersionUID = -5405798080040422910L;

	/**
	 * seqno field
	 */
	protected Long seqno;

	/**
	 * method field
	 */
	protected String method;

	/**
	 * Constructor.
	 */
	public CSeq() {
		super(CSEQ);
	}

	/**
	 * Constructor given the sequence number and method.
	 *
	 * @param seqno is the sequence number to assign.
	 * @param method is the method string.
	 */
	public CSeq(long seqno, String method) {
		this();
		this.seqno = new Long(seqno);
		this.method = SIPRequest.getCannonicalName(method);
	}

	/**
	 * Compare two cseq headers for equality.
	 * @param other Object to compare against.
	 * @return true if the two cseq headers are equals, false
	 * otherwise.
	 */
	public boolean equals(Object other) {
		
		if (other instanceof CSeqHeader) {
			final CSeqHeader o = (CSeqHeader) other;
			return this.getSeqNumber() == o.getSeqNumber()
				&& this.getMethod().equals( o.getMethod() );
		}
		return false;
	}

	/**
	 * Return canonical encoded header.
	 * @return String with canonical encoded header.
	 */
	public String encode() {
		return headerName + COLON + SP + encodeBody() + NEWLINE;
	}

	/**
	 * Return canonical header content. (encoded header except headerName:)
	 *
	 * @return encoded string.
	 */
	public String encodeBody() {
		return encodeBody(new StringBuffer()).toString();
	}

	protected StringBuffer encodeBody(StringBuffer buffer) {
		return buffer.append(seqno).append(SP).append(method.toUpperCase());
	}

	/**
	 * Get the method.
	 * @return String the method.
	 */
	public String getMethod() {
		return method;
	}

	/*
	 * (non-Javadoc)
	 * @see javax.sip.header.CSeqHeader#setSequenceNumber(long)
	 */
	public void setSeqNumber(long sequenceNumber)
		throws InvalidArgumentException {
		if (sequenceNumber < 0 )
			throw new InvalidArgumentException(
				"JAIN-SIP Exception, CSeq, setSequenceNumber(), "
					+ "the sequence number parameter is < 0 : " + sequenceNumber);
		else if ( sequenceNumber >  ((long)1)<<32 - 1) 
			throw new InvalidArgumentException(
					"JAIN-SIP Exception, CSeq, setSequenceNumber(), "
						+ "the sequence number parameter is too large : " + sequenceNumber);
		
		seqno = new Long(sequenceNumber);
	}

	/**
	 * For backwards compatibility
	 */
	public void setSequenceNumber(int sequenceNumber) throws InvalidArgumentException {
		this.setSeqNumber( (long) sequenceNumber );
	}
	
	/*
	 * (non-Javadoc)
	 * @see javax.sip.header.CSeqHeader#setMethod(java.lang.String)
	 */
	public void setMethod(String meth) throws ParseException {
		if (meth == null)
			throw new NullPointerException(
				"JAIN-SIP Exception, CSeq"
					+ ", setMethod(), the meth parameter is null");
		this.method = SIPRequest.getCannonicalName(meth);
	}

	/*
	 * (non-Javadoc)
	 * @see javax.sip.header.CSeqHeader#getSequenceNumber()
	 */
	public int getSequenceNumber() {
		if (this.seqno == null)
			return 0;
		else
			return this.seqno.intValue();
	}

	
	

	public long getSeqNumber() {
		return this.seqno.longValue();
	}

	
}

